Brew 是OS X 上类似apt-get以及yum的一个软件包管理器，它依托于Github………………
所以，虽然你侥幸下载到了 brew，但你肯定是无法更新 brew 的。原因你懂。不过虽然不能更新 brew，但这只是指brew这个管理器本身罢了，软件还是可以安装的。但由于无法使用 brew update 也就无法更新软件……我们有必要来给 brew 换源。
安装、卸载homebrew
ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/uninstall)"sudo rm -rf /usr/local/
替换homebrew默认源
cd /usr/localgit remote set-url origin git://mirrors.ustc.edu.cn/brew.git
替换homebrew-core默认源
cd /usr/local/Library/Taps/homebrew/homebrew-coregit remote set-url origin git://mirrors.ustc.edu.cn/homebrew-core.git
替换homebrew-cask默认源
cd /usr/local/Homebrew/Library/Taps/caskroom/homebrew-caskgit remote set-url origin git://mirrors.ustc.edu.cn/homebrew-cask.git
替换homebrew bottles默认源
echo 'export HOMEBREW_BOTTLE_DOMAIN=https://mirrors.ustc.edu.cn/homebrew-bottles' >> ~/.bashrcsourch ~/.bashrc
PS:
https://servers.ustclug.org/2016/01/mirrors-add-homebrew-bottles-source/
https://www.logcg.com/archives/1301.html
https://mirrors.tuna.tsinghua.edu.cn/help/homebrew/
https://mirrors.tuna.tsinghua.edu.cn/help/homebrew-bottles/
https://lug.ustc.edu.cn/wiki/mirrors/help/homebrew-bottles